1. Field of the Invention
An embodiment of the present invention relates to a photodetector.
2. Description of the Related Art
In recent years, development of a technique of a device to which data is inputted by incidence of light (the device also referred to as a photodetector) has been promoted.
As an example of a photodetector, a photodetector provided with a photodetector circuit (also referred to as a photosensor) can be given (e.g., Patent Document 1). The above photodetector detects illuminance of light incident on the photodetector circuit and generates a data signal in accordance with the illuminance of light. When the photodetector is provided with a photodetector circuit and a display circuit, a display state of the display circuit can be controlled by using a data signal generated by the photodetector circuit, and thus the photodetector can function as a touch panel, for example.